Restrictive vs. Liberal Red Blood Cell Transfusion Strategy in Patients with Acute Myocardial Infarction and Anemia: An Updated Systematic Review and Meta-analysis of Randomized Control Trials

Background: Anemia is a common condition in patients with acute myocardial infarction (AMI), with prevalence rates ranging from 15% to 43%. It is associated with increased mortality and adverse cardiovascular outcomes, particularly in acute coronary syndrome (ACS), where it is frequently linked with comorbidities like heart failure, hypertension, chronic kidney disease, and malignancy. Anemia reduces oxygen delivery, exacerbates heart muscle damage, and heightens the inflammatory response, increasing the risk of cardiovascular events. Objectives: This study aims to assess the safety and impact of liberal versus restrictive blood transfusion (BT) strategies in patients with AMI and anemia, particularly concerning mortality and adverse outcomes such as infection, circulatory overload, transfusion reactions, and reinfarction. Methodology: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted, focusing on adult patients with AMI who received either liberal or restrictive transfusions. Primary outcomes analyzed include all-cause mortality and overall safety, with secondary outcomes assessing complications related to transfusion, including reinfarction due to increased thrombogenicity. Results: Prior studies indicate comparable outcomes between restrictive and liberal transfusion strategies concerning overall mortality and long-term survival. However, restrictive transfusion has been associated with a higher risk of in-hospital mortality, though recent trials show no significant superiority of liberal transfusion in terms of mortality. Conclusion: Both liberal and restrictive transfusion strategies show similar long-term mortality outcomes in AMI patients with anemia. However, the risk of in-hospital mortality may be higher with restrictive transfusion, necessitating further investigation to establish optimal transfusion practices.